// InitialState.java
class InitialState implements State {
    @Override
    public void handleChar(StringExtractor extractor, char c) {
        if (c == '"') {
            System.out.println("开始提取字符串...");
            extractor.clearCurrentString();
            extractor.setState(new ExtractingState());
        } else {
            // 忽略非引号字符
        }
    }
}